I’ll Have What S/he’s Having: A Case Study of a Social Trading Network

Opinion leaders of an investment network can have a significant impact on capital mar-kets because their investment decisions are adopted by their peers and trigger large trad-ing cascades, increasing herding behavior and comovement among stock returns. This paper analyzes the interaction-based relations of traders from a large social trading plat-form and identifies the driving forces and the opinion leaders within a large online trading network as the nodes with the highest centrality and the highest force of infection, respec-tively. Relying on recent insights from epidemiological research, I maintain that central-ity identifies the most central traders in the network, while the expected force quantifies the most influential traders and their spreading power. I study the behavior and charac-teristics that set central and influential traders apart from other traders. The ability to identify focal points and their trading behavior within a trading network is important for investors, investment advisers, and policy makers.